Thiophosphatosuccinimides



Patented June 30, 1953 TIHOPHOSPHATOSUCCINIMIDES Erick I. Hoegberg, Greenwich, Conn, assignor to American Cyanamid Company, New York, N. Y.,

a corporation of Maine No Drawing. Application August 29, 1951, Serial No. 244,277

cycloaliphatic hydrocarbon radicals. Typical examples of these radicals are methyl, ethyl, npropyl, isopropyl, n-butyl. isobutyl, sec.-amyl, nhexyl, Z-ethylhexyl, n-octyl, n-decyl, n-dodecyl, n-octadecyl, oleyl, cetyl, ceryl, allyl, cyclohexyl, benzyl, phenyl, pchlorophenyl, tolyl, xylyl, naphthyl and naphthylmethyl.

The thiophosphatosuccinimides of this invention may be readily prepared by reacting an acid phosphate of the formula in which R1 and R2 have the meaning shown above. with an Nsubstituted'ma1eimide of the formula l HO in which'Ra has the meaning shown above.

A typical reaction in which 0,0-dimethyl dithiophosphoric' acid is reacted with N -ethylmaleimide to produce a-'(0,0-dimethyl dithiophosphato)-N-ethylsuccinimide may be illustrated as follows; .11.

The reaction is somewhat exothermic and may 6 Claims- (Cl. 260-3265) be readily controlled by carrying it out in the presence of an inert solvent. It is also advantageous to employ a solvent when one or both of the reactants are solids. Such solvents include saturated aliphatic esters such as ethyl acetate, amyl acetate, Z-ethylhexyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, and isopropyl butyrate; saturated aliphatic nitriles such as acetonitrile and propionitrile, dioxane, benzene, nitrobenzene, chlorbenzene, toluene, xylene, chloroform, and carbon tetrachloride.

The reaction is preferably carried out at a temperature within the range ofv from about 20 to 150 C. Howeventemperatures outside of this range may be employed depending upon the type of reactants and solvents utilized.

The following examples will further illustrate the invention.

' Example 1 12.9 of N-ethylma-le'unide were added gradu ally to 7.6 g. of 0,0-dimethyl dithiophosphoric acid (92 purity). Heat was evolved and the temperature of the mixture rose to about C. After the reaction had subsided, the mixture was allowed to stand at room temperature for about 16 hours, then dissolved in 50 cc. of benzene, washed twice with 10% sodium bicarbonate solution and once with water. The benzene solution was stripped of solvent by distillation at reduced pressure, first at 20-30 mm.. and finally at 0.5 mm. pressure. The residual solid was recrystallized from 25 cc. of'ethyl alcohol, giving 10.3 g. (72% yield) of a-(0,0-dimethyl dithiophosphato)-N-ethyls uccinimide, a colorless crystalline product meltin at 59-60 C.

Example '2 The procedure of Example 1 was employed using 15.7 g. of N-(2-ethy1hexyl) maleimide and 15.5 g. of 0,0-diethyl dithiophosphoric acid purity). The residual product, a-'(0,0-\diethyl dithiophosphato) N (Z-ethylhexyD-succinimide, weighing 25.3 g. (85% yield) was a viscous, straw-colored liquid having a refractive index 71, 1.50831.

Example 3 A mixture consisting of 18.8 g. of 0,0-diethyl dithiophosphoric acid (95.8% purity) and 34.9 g. of N-(n-octadecyl) maleimide was heated at 65 C. for 4 hours, and thenallowed to stand overnight at room temperature. The reaction mixture was dissolved in cc. of benzene, washed twice with 10% sodium bicarbonate solu tion and dried over anhydrous calcium sulfate. The benzene solution was stripped of solvent by distillation at reduced pressure. The residual product, a-(0,0-diethy1 dithiophosphato) -N- (noctadecyl) -succinimide, was a viscous dark brown liquid.

Example 4 A mixture consisting of 10 g. of 0,0-diethyl dithiophosphoric acid (95% purity) and 10.4 g. of N-( l-chlorophenyl) maleimide was heated for five hours at 65 C., and then allowed to stand for 16 hours at room temperature. The solid reaction product was recrystallized-from lw cc.

of methyl alcohol, giving 15.5 g. (79% yield) of N (4 chlorophenyl) ea-(0,0-die thyl dithiophosphato) -succin.imide, a colorless crystalline-"mate rial melting at 905-92" C.

Example 5 The procedure of. Examples. was employed using 9.8 g. of 0,0-diethyl. dith'iophosphoric acid (95% purity) and 10.9 g. of N-('4-nitrophenyl)-' maleimide. 16.1 g. (80% yield) of a-(0,0-diethyl dithiophosphato) N (4,-nitrophenyD-succinimide were obtained. The product was a color'- less crystalline material melting at 118.5-1195? C.

Example 6 A mixture consisting of 2.5 g. of 0,-'-diethyl dithiophosphoric acid (90% purity) and 2.9 g. of N-(p-sulfamylphenyl)maleimide was allowed to stand at room temperature for days. The solid reaction product was recrystallized from acetone, giving 2.3 g. of'a-(0,0-diethyl dithiophosphato N-(p-sulfamylphenyl)-succinimide, a colorless crystalline material melting at l99-200 C. with decomposition. 7

Example 7 The procedure of Example 3. was. employed using 9.2 goof 0,0-bis(2-ethy1hexyl) dithiopho's-T phoric acid (94.5% urity) and 3.8 g. of N-isobutylmaleimide. The residual product, a-[0,0- bis(2 ethylhexyl) dithiophosphato]=N=isobutylsuccinimide, weighing-11.5 'g. (93% yield) was an amber-colored liquid having a refractive index 11. 1.4958.

Example!) A mixture consisting of 40 g. of 0,0-di-n-tetradecyl dithiophosphoric acid (87.1% purity) and 11.5 g. of N-phenylmaleimide was heated on a steam bath for 5 hours, and then allowed to stand 4 overnight at room temperature. The reaction mixture was dissolved in 100 cc. of benzene, washed twice with 10% sodium bicarbonate solution and dried over anhydrous sodium sulfate. The benzene solution was stripped of solvent by distillation at reduced pressure. product a-(0,0-di-n-tetradecyl dithiophosphato) N-phenylsuccinimide, was a dark brown liquid having a refractive index n 1.5055.

Example 10 A mixture consisting of 28.2 g. of 0,0-diphenyl dithiophosphoric acid, 17.3 g. of N-phenylmaleimide and cc. of benzene was heated on a steam bath at reflux for one hour, and then allowed to stand at room temperature for 16 hours. The reaction mixture was diluted with 100 cc. of benzene, washed with 10% sodium bicarbonate solution and dried over anhydrous magnesium sulfate. The benzene solution was stripped of solvent by distillation at reduced pressure. The residual product, a-(ILO-diphenyI dithiophospha'to) N-phenylsuccinimide, weighing 41 g. yield) was a viscous, brown liquid having a refractive index 71 1.6140.

The thiophosphatosuccinimides of the present invention are adapted for various uses, more particularly as insecticides, fungicides, plasticizers, corrosion inhibitors, flotation agents, and petroleum additives.

While the invention has been described with particular reference to specific'embodiments, it is to be understood that it is not to be limited thereto but is to be construed broadly and restricted solely 'by the scope of the appended claims.

Iclaim: 1. Thiophosphatosuccinimides ofthe general formula R10 s v t"-soHoo R10 N"'R3 CHzCO in which R1, R2, and R3, are chosen from the group consisting of 'alkyl, aralkyl, aryl, and alkaryl radicals.

2. a-(0,0-dimethy1 dithiophosphato) -N-ethylsuccinimide.

3. a.- (0,0-diethy1 dithiophosphato) -N-(2-eth- A ylhexyl) -succinimide.

4. a. [0,0- bis(Z-ethylhexyl)v N 'isobutylsuccinimide.

5. a-(0,0-di-n-tetradecyl dithiophosphato) -N- phenylsuccinimide.

6. a- (0,0-diphenyl dithiophosphato)-N-phenylsuccinimide.

ERICK I. HOEGBERG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date OTHER REFERENCES Chemical Abstracts, vol. 44, p.550 citing Marion, J. Chem. Soc. (London), 1949,.pp. 15l5-l516.

. The residual dithiophosphato] 

1. THIOPHOSPHATOSUCCINIMIDES OF THE GENERAL FORMULA 